Historicism is an approach to explaining the existence of phenomena, especially social and cultural practices (including ideas and beliefs), by studying their history; that is, by studying the process by which they came about. The term is widely used in philosophy, anthropology, and sociology.
This historical approach to explanation differs from and complements the approach known as functionalism, which seeks to explain a phenomenon, such as for example a social form, by providing reasoned arguments about how that social form fulfills some function in the structure of a society. In contrast, rather than taking the phenomenon as a given and then seeking to provide a justification for it from reasoned principles, the historical approach asks "Where did this come from?" and "What factors led up to its creation?"; that is, historical explanations often place a greater emphasis on the role of process and contingency.
Historicism is often used to help contextualize theories and narratives, and is a useful tool to help understand how social and cultural phenomena came to be.
The historicist approach differs from individualist theories of knowledge such as strict empiricism and de-contextualised rationalism, which neglect the role of traditions. Historicism may be contrasted with reductionist theories—which assume that all developments can be explained by fundamental principles (such as in economic determinism)—or with theories that posit that historical changes occur entirely at random.
The term historicism (Historismus) was coined by German philosopher Karl Wilhelm Friedrich Schlegel. Over time, what historicism is and how it is practiced have developed different and divergent meanings. Elements of historicism appear in the writings of French essayist Michel de Montaigne (1533–1592) and Italian philosopher G. B. Vico (1668–1744), and became more fully developed with the dialectic of Georg Wilhelm Friedrich Hegel (1770–1831), influential in 19th-century Europe. The writings of Karl Marx, influenced by Hegel, also include historicism.